The present invention relates to a latch element for restraining pieces of cargo against any tendency to be displaced on the floor in a freight compartment of an aircraft.
Large aircraft of the jumbo jet variety are usually provided with a large area cargo space, and restraining freight and cargo against movement in that space is a considerable problem. This is particularly so in the case of a wide-body aircraft in which the compartment is normally used for passengers but is to serve also as cargo space. The invention relates particularly to the restraining of cargo by means of structure which is releasably connectable to those floor rails to which normally the seating is fastened. Moreover, the restraining structure should permit retraction so that freight can pass over it.
Latching devices of the type to which the invention pertains are usually called YZ restrainers or latches, wherein Y denotes a lateral direction in the aircraft and Z is the vertical direction. Restraining requires immobilizing freight such as pallets or containers as against displacement in the Y- and Z-directions; within this coordinate scheme, X is the direction of movement of freight in the cargo space, and restraint may not be required, at least not as to individual pieces.
Considering the problem in some detail, it is apparent that the restrainers must be provided to accommodate pallets and containers; also, containers come in different widths. Thus, one has suggested to provide a plurality of such Y/Z latches, e.g., latches arranged in rows, with several latches in each Y-row. Only respective outer latches are used, depending upon the width of the container, etc.; and all latches not used can be rolled over.
Another problem is that wide-body planes are sometimes used as all-cargo planes, at other times for passenger transport. Hence, such a plane should be rather speedily adaptable for one and the other purpose. It is, therefore, customary to use floor rails for selectively fastening seats or cargo restrainers. In the latter case, one uses particular traverses. Since the latches have to have at least a minimum size, it was found difficult to use several latches on a traverse and in sufficient density to accommodate pieces of cargo that differ in size to a limited extent only. This, in turn, limits universality of such a restraining system as such.
Generally, as to the state of the art, reference is made to U.S. Pat. No. 3,709,450.